fs/xfs/scrub/symlink.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <djwong@kernel.org>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_log_format.h"
  13 #include "xfs_trans.h"
  14 #include "xfs_inode.h"
  15 #include "xfs_symlink.h"
  16 #include "xfs_health.h"
  17 #include "xfs_symlink_remote.h"
  18 #include "scrub/scrub.h"
  19 #include "scrub/common.h"
  20 #include "scrub/health.h"
  21 #include "scrub/repair.h"
  22
  23 /* Set us up to scrub a symbolic link. */
  24 int
  25 xchk_setup_symlink(
  26         struct xfs_scrub        *sc)
  27 {
  28         unsigned int            resblks = 0;
  29         int                     error;
  30
  31         /* Allocate the buffer without the inode lock held. */
  32         sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
  33         if (!sc->buf)
  34                 return -ENOMEM;
  35
  36         if (xchk_could_repair(sc)) {
  37                 error = xrep_setup_symlink(sc, &resblks);
  38                 if (error)
  39                         return error;
  40         }
  41
  42         return xchk_setup_inode_contents(sc, resblks);
  43 }
  44
  45 /* Symbolic links. */
  46
  47 int
  48 xchk_symlink(
  49         struct xfs_scrub        *sc)
  50 {
  51         struct xfs_inode        *ip = sc->ip;
  52         struct xfs_ifork        *ifp;
  53         loff_t                  len;
  54         int                     error = 0;
  55
  56         if (!S_ISLNK(VFS_I(ip)->i_mode))
  57                 return -ENOENT;
  58
  59         if (xchk_file_looks_zapped(sc, XFS_SICK_INO_SYMLINK_ZAPPED)) {
  60                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  61                 return 0;
  62         }
  63
  64         ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
  65         len = ip->i_disk_size;
  66
  67         /* Plausible size? */
  68         if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  69                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  70                 return 0;
  71         }
  72
  73         /* Inline symlink? */
  74         if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
  75                 if (len > xfs_inode_data_fork_size(ip) ||
  76                     len > strnlen(ifp->if_data, xfs_inode_data_fork_size(ip)))
  77                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  78                 return 0;
  79         }
  80
  81         /* Remote symlink; must read the contents. */
  82         error = xfs_symlink_remote_read(sc->ip, sc->buf);
  83         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  84                 return error;
  85         if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  86                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  87
  88         /* If a remote symlink is clean, it is clearly not zapped. */
  89         xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_SYMLINK_ZAPPED);
  90         return 0;
  91 }